experiment with transporting uncompressed a/v together in a matroska stream

1 files changed, 167 insertions, 0 deletions

diff --git a/voctocore/lib/videomix.py b/voctocore/lib/videomix.py
new file mode 100644
index 0000000..bcac7d2
--- /dev/null
+++ b/voctocore/lib/videomix.py
@@ -0,0 +1,167 @@
+#!/usr/bin/python3
+import logging
+from gi.repository import Gst
+from enum import Enum
+
+from lib.config import Config
+
+class CompositeModes(Enum):
+	fullscreen = 0
+	side_by_side_equal = 1
+
+class VideoMix(object):
+	log = logging.getLogger('VideoMix')
+
+	mixingPipeline = None
+
+	caps = None
+	names = []
+
+	compositeMode = CompositeModes.fullscreen
+	sourceA = 0
+	sourceB = 1
+
+	def __init__(self):
+		self.caps = Config.get('mix', 'videocaps')
+
+		self.names = Config.getlist('sources', 'video')
+		self.log.info('Configuring Mixer for %u Sources', len(self.names))
+
+		pipeline = """
+			videomixer name=mix !
+			{caps} !
+			textoverlay text=mixer halignment=left valignment=top ypad=175 !
+			intervideosink channel=video_mix
+		""".format(
+			caps=self.caps
+		)
+
+		for idx, name in enumerate(self.names):
+			pipeline += """
+				intervideosrc channel=video_{name}_mixer !
+				{caps} !
+				videoscale !
+				capsfilter name=caps_{idx} !
+				mix.
+			""".format(
+				name=name,
+				caps=self.caps,
+				idx=idx
+			)
+
+		self.log.debug('Creating Mixing-Pipeline:\n%s', pipeline)
+		self.mixingPipeline = Gst.parse_launch(pipeline)
+
+		self.log.debug('Initializing Mixer-State')
+		self.updateMixerState()
+
+		self.log.debug('Launching Mixing-Pipeline:\n%s', pipeline)
+		self.mixingPipeline.set_state(Gst.State.PLAYING)
+
+	def updateMixerState(self):
+		if self.compositeMode == CompositeModes.fullscreen:
+			self.updateMixerStateFullscreen()
+
+		if self.compositeMode == CompositeModes.side_by_side_equal:
+			self.updateMixerStateSideBySideEqual()
+
+	def updateMixerStateFullscreen(self):
+		self.log.info('Updating Mixer-State for Fullscreen-Composition')
+
+		noScaleCaps = Gst.Caps.from_string('video/x-raw')
+
+		for idx, name in enumerate(self.names):
+			alpha = int(idx == self.sourceA)
+
+			self.log.debug('Setting Mixerpad %u to x/y=0 and alpha=%0.2f', idx, alpha)
+			mixerpad = self.mixingPipeline.get_by_name('mix').get_static_pad('sink_%u' % idx)
+			mixerpad.set_property('alpha', alpha )
+			mixerpad.set_property('xpos', 0)
+			mixerpad.set_property('ypos', 0)
+
+			self.log.debug('Resetting Scaler %u to non-scaling', idx)
+			capsfilter = self.mixingPipeline.get_by_name('caps_%u' % idx)
+			capsfilter.set_property('caps', noScaleCaps)
+
+	def getInputVideoSize(self):
+		caps = Gst.Caps.from_string(self.caps)
+		struct = caps.get_structure(0)
+		_, width = struct.get_int('width')
+		_, height = struct.get_int('height')
+
+		return width, height
+
+	def updateMixerStateSideBySideEqual(self):
+		self.log.info('Updating Mixer-State for Side-by-side-Equal-Composition')
+
+		width, height = self.getInputVideoSize()
+		gutter = int(width / 100)
+
+		self.log.debug('Video-Size parsed as %u/%u, Gutter calculated to %upx', width, height, gutter)
+
+		targetWidth = int((width - gutter) / 2)
+		targetHeight = int(targetWidth / width * height)
+
+		ycenter = (height - targetHeight) / 2
+		xa = 0
+		xb = width - targetWidth
+
+		scaleCaps = Gst.Caps.from_string('video/x-raw,width=%u,height=%u' % (targetWidth, targetHeight))
+		noScaleCaps = Gst.Caps.from_string('video/x-raw')
+
+		for idx, name in enumerate(self.names):
+			mixerpad = self.mixingPipeline.get_by_name('mix').get_static_pad('sink_%u' % idx)
+
+			if idx == self.sourceA:
+				x = xa
+				y = ycenter
+				caps = scaleCaps
+				alpha = 1
+
+				self.log.debug('Setting Mixerpad %u to x/y=%u/%u and alpha=%0.2f', idx, x, y, alpha)
+				self.log.debug('Setting Scaler %u to %u/%u', idx, targetWidth, targetHeight)
+
+			elif idx == self.sourceB:
+				x = xb
+				y = ycenter
+				caps = scaleCaps
+				alpha = 1
+
+				self.log.debug('Setting Mixerpad %u to x/y=%u/%u and alpha=%0.2f', idx, x, y, alpha)
+				self.log.debug('Setting Scaler %u to %u/%u', idx, targetWidth, targetHeight)
+
+			else:
+				x = 0
+				y = 0
+				caps = noScaleCaps
+				alpha = 0
+
+				self.log.debug('Setting Mixerpad %u to x/y=%u/%u and alpha=%0.2f', idx, x, y, alpha)
+				self.log.debug('Resetting Scaler %u to non-scaling', idx)
+
+			mixerpad.set_property('alpha', alpha)
+			mixerpad.set_property('xpos', x)
+			mixerpad.set_property('ypos', y)
+
+			capsfilter = self.mixingPipeline.get_by_name('caps_%u' % idx)
+			capsfilter.set_property('caps', caps)
+
+	def setVideoA(self, source):
+		# swap if required
+		if self.sourceB == source:
+			self.sourceB = self.sourceA
+
+		self.sourceA = source
+		self.updateMixerState()
+
+	def setVideoB(self, source):
+		# swap if required
+		if self.sourceA == source:
+			self.sourceA = self.sourceB
+
+		self.sourceB = source
+		self.updateMixerState()
+
+	def setCompositeMode(self, mode):
+		self.compositeMode = mode
+		self.updateMixerState()